It is known in the art to monitor grouped objects in logistical systems by attaching simple transponders to the objects that are able to communicate via a remote gateway with a superordinate information system. FIG. 1 shows schematically a system of this kind with the transponders 2 fitted to the objects 1, the gateway 3 and also the information system 4. The connection between the transponders 2 and the gateway 3 takes place via a wireless medium. Communication 5 is indicated in the figure. With small distances and few requirements, thus, for example, in the identification of pallets and outer packagings with the aid of so-called smart labels, the transponders 2 do not make use of any kind of energy storage system and extract the energy necessary for communications 5 directly from a magnetic or electromagnetic field generated by a base station. However for larger distances between the transponders 2 and the gateway 3 batteries or accumulators are required for operation of the transponders 2 and communications 5. If the exact position of the logistical objects 1 is required in the information system 4, then each individual object 1 must undertake a determination of location with the aid of a suitable localisation infrastructure 6 and transmit the position data wirelessly to the gateway 3.
In a system of this kind numerous problems occur in which up to now have prevented any practical use in logistical systems. Thus the individual objects 1 can mask one another in terms of radio signals, so that undistorted communication with the gateway 3 and the 100% communications security required in many cases are no longer guaranteed. Likewise any localisation is prevented as a result of the masking of radio signals, for example, with the stacking of containers in a ship's hull if localisation should take place via a satellite navigation system. Since each individual object 1 must communicate with the gateway 3 over comparatively long distances, very high communications costs are generated, in particular in applications that are spatially very widely distributed. The use of energy storage systems repeatedly requires expensive maintenance processes during the service life in terms of replacing batteries or charging the accumulators. The energy reserve is in many cases too quickly exhausted from the point of view of the application.
For a seamless flow of information and goods it is necessary that object and information system can communicate at all times, the identity and the state of the individual object are known at all times in the information system, and the position of the object is likewise stored in an up-to-date manner in the data structures. It is true that this requirement can in principle be realised by the attachment of microelectronic modules, such as the active transponders already cited, onto the objects. However, in practice the widespread use of microelectronic modules of this kind is impeded by the high energy consumption already referred to above, together with a limited energy reserve.